Plasma samples were collected for quantitative HIV-1 RNA analysis at Week 16. The analysis was performed using the time to loss of virological response (TLOVR) dataset. In the TLOVR dataset, participant responses at a specified threshold of HIV-1 RNA (<50 copies/mL) are determined by using the Food and Drug Administration's TLOVR algorithm. Using the TLOVR algorithm, participants are considered to have failed on therapy if they never achieved confirmed RNA levels below the threshold, if they had confirmed rebound of RNA above the threshold, if they made a non-permitted change in background regimen, or if they permanently discontinued investigational product for any reason. Data are reported per the Week 16 report. In later cuts of the data, the Week 16 values may have changed (because of the nature of the TLOVR algorithm).

Plasma samples were collected for quantitative HIV-1 RNA analysis at Baseline and Week 2. Viral change is defined as the change in plasma HIV-1 RNA over the initial 2 weeks of treatment, calculated as the value at Week 2 minus the value at Baseline.

Number of Participants With New HIV-associated Conditions of the Indicated Class [ Time Frame: From Baseline up to Week 96 ] [ Designated as safety issue: No ]

HIV-associated conditions were assessed according to the Centers for Disease Control and Prevention (CDC) HIV-1 classification system. Category (CAT) A: one or more of the following conditions (CON), without any CON listed in Categories B and C: asymptomatic HIV infection, persistent generalized lymphadenopathy, acute (primary) HIV infection with accompanying illness or history of acute HIV infection. CAT B: symptomatic CON that are attributed to HIV infection or are indicative of a defect in cell-mediated immunity; or that are considered by physicians to have a clinical course or to require management that is complicated by HIV infection; and not included among CON listed in clinical CAT C. CAT C: the clinical CON listed in the acquired immunodeficiency syndrome (AIDS) surveillance case definition.

Number of Participants With the Indicated Type of HIV-1 Disease Progression (AIDS or Death) [ Time Frame: From Baseline up to Week 96 ] [ Designated as safety issue: No ]

Clinical disease progression (CDP) was assessed according to the Centers for Disease Control and Prevention (CDC) HIV-1 classification system. Category (CAT) A: one or more of the following conditions (CON), without any CON listed in Categories B and C: asymptomatic HIV infection, persistent generalized lymphadenopathy, acute (primary) HIV infection with accompanying illness or history of acute HIV infection. CAT B: symptomatic CON that are attributed to HIV infection or are indicative of a defect in cell-mediated immunity; or that are considered by physicians to have a clinical course or to require management that is complicated by HIV infection; and not included among CON listed in clinical CAT C. CAT C: the clinical CON listed in the AIDS surveillance case definition. Indicators of CDP were defined as: CAT A at Baseline (BS) to CAT B event (EV), CAT A at BS to a CAT C EV; CAT B at BS to a CAT C EV; CAT C at BS to a new CAT C EV; or CAT A, B, or C at BS to death.

Plasma samples were collected for quantitative HIV-1 RNA analysis at Baseline (Day 1), Week 1, Week 2, Week 4, Week 8, Week 12, Week 16, Week 20, Week 24, Week 32, Week 40, Week 48, Week 60, Week 72, Week 84, and Week 96. The analysis was performed using the time to loss of virological response (TLOVR) dataset. In the TLOVR dataset, participant responses at a specified threshold of HIV-1 RNA (<50 copies/mL) are determined by using the Food and Drug Administration's TLOVR algorithm. Using the TLOVR algorithm, participants are considered to have failed on therapy if they never achieved confirmed RNA levels below the threshold, if they had confirmed rebound of RNA above the threshold, if they made a non-permitted change in background regimen, or if they permanently discontinued investigational product for any reason.

Plasma samples were collected for quantitative HIV-1 RNA analysis at Baseline (Day 1), Week 1, Week 2, Week 4, Week 8, Week 12, Week 16, Week 20, Week 24, Week 32, Week 40, Week 48, Week 60, Week 72, Week 84, and Week 96. The analysis was performed using the time to loss of virological response (TLOVR) dataset. In the TLOVR dataset, participant responses at a specified threshold of HIV-1 RNA (<400 c/mL) are determined by using the Food and Drug Administration's TLOVR algorithm. Using the TLOVR algorithm, participants are considered to have failed on therapy if they never achieved confirmed RNA levels below the threshold, if they had confirmed rebound of RNA above the threshold, if they made a non-permitted change in background regimen, or if they permanently discontinued investigational product for any reason.

Number of Participants With Any Adverse Event (AE) and Any Serious Adverse Events (SAE) [ Time Frame: From Baseline up to Week 96/Early Withdrawal ] [ Designated as safety issue: No ]

An adverse event (AE) is defined as any untoward medical occurrence in a participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. A serious adverse event (SAE) is defined as any untoward medical occurrence that, at any dose: results in death; is life threatening, requires hospitalization or prolongation of existing hospitalization, results in disability/incapacity; or is a congenital anomaly/birth defect. All clinically suspected cases of hypersensitivity reaction to abacavir in participants receiving abacavir/lamivudine were reported as SAEs. Medical or scientific judgment was to have been exercised in other situations. Refer to the general AE/SAE module for a list of AEs (occuring at a frequency threshold >=3%) and SAEs.

Number of Participants With the Indicated Grade 1 to Grade 4 Treatment-emergent Clinical Chemistry and Hematology Toxicities [ Time Frame: From Baseline up to Week 96/Early Withdrawal ] [ Designated as safety issue: No ]

Blood samples were collected for the measurement of clinical chemistry and hematology parameters. Toxicities were graded for severity according to the Division of AIDS (DAIDS) toxicity scales as: Grade 1 (mild), Grade 2 (moderate), Grade 3 (severe), or Grade 4 (potentially life threatening).

Number of Participants With the Indicated Treatment-emergent Integrase (IN) Mutations Detected at the Time of Protocol-defined Virologic Failure (PDVF), as a Measure of Genotypic Resistance [ Time Frame: From Baseline up to Week 96/Early Withdrawal ] [ Designated as safety issue: No ]

For participants meeting one of the criteria for PDVF, plasma samples collected at the time point of virologic failure were tested to evaluate any potential genotypic and/or phenotypic evolution of resistance. PDVF was defined as (A) Virologic Non-response: a decrease in plasma HIV-1 RNA of <1 log10 copies/mL by Week 4, with subsequent confirmation, unless plasma HIV-1 RNA is <400 copies/mL; confirmed plasma HIV-1 RNA levels >=400 copies/mL on or after Week 24 without evidence of prior suppression to <400copies/mL or (B) Virologic Rebound: confirmed rebound in plasma HIV-1 RNA levels to >=400 copies/mL after prior confirmed suppression to <400 copies/mL; confirmed plasma HIV-1 RNA levels >0.5 log10 copies/mL above the nadir value, where nadir is the lowest HIV-1 value >=400 copies/mL.

Number of Participants With the Indicated Treatment-emergent Major Mutations of Other Classes Detected at the Time of Protocol-defined Virologic Failure (PDVF), as a Measure of Genotypic Resistance [ Time Frame: From Baseline up to Week 96/Early Withdrawal ] [ Designated as safety issue: No ]

For participants meeting one of the criteria for PDVF, plasma samples collected at the time point of virologic failure were tested to evaluate any potential genotypic and/or phenotypic evolution of resistance. PDVF was defined as (A) Virologic Non-response: a decrease in plasma HIV-1 RNA of <1 log10 copies/mL by Week 4, with subsequent confirmation, unless plasma HIV-1 RNA is <400 copies/mL; confirmed plasma HIV-1 RNA levels >=400 copies/mL on or after Week 24 without evidence of prior suppression to <400copies/mL or (B) Virologic Rebound: confirmed rebound in plasma HIV-1 RNA levels to >=400 copies/mL after prior confirmed suppression to <400 copies/mL; confirmed plasma HIV-1 RNA levels >0.5 log10 copies/mL above the nadir value, where nadir is the lowest HIV-1 value >=400 copies/mL.

Number of Participants With the Indicated Fold Increase in DTG FC (Fold Change in IC50 Relative to Wild-type Virus) at the Time of PDVF, as a Measure of Post-Baseline Phenotypic Resistance [ Time Frame: From Baseline up to Week 96/Early Withdrawal ] [ Designated as safety issue: No ]

The FC in IC50 (50% inhibitory concentration) for DTG relative to wild-type virus was determined for virus isolated at Baseline and at the time of PDVF. Fold increase in DTG FC at the time of PDVF was derived as the PDVF FC/Baseline FC ratio. PDVF was defined as (A) Virologic Non-response: a decrease in plasma HIV-1 RNA of <1 log10 copies/mL by Week 4, with subsequent confirmation, unless plasma HIV-1 RNA is <400 copies/mL; confirmed plasma HIV-1 RNA levels >=400 copies/mL on or after Week 24 without evidence of prior suppression to <400copies/mL or (B) Virologic Rebound: confirmed rebound in plasma HIV-1 RNA levels to >=400 copies/mL after prior confirmed suppression to <400 copies/mL; confirmed plasma HIV-1 RNA levels >0.5 log10 copies/mL above the nadir value, where nadir is the lowest HIV-1 value >=400 copies/mL.

Blood samples for the determination of plasma DTG concentration were collected from the participants randomized to receive DTG, at the following time points: pre-dose and 2-4 hours post-dose at Weeks 2, Week 12, and Week 24. Because PK was assessed for DTG, no participants in the EFV treatment group were analyzed. The Pharmacokinetic (PK) Summary Population is comprised of all participants who received DTG and underwent intensive PK sampling or limited PK sampling during the study and provided evaluable DTG PK parameters.

The area under the time concentration curve over the dosing interval (AUC[0-tau]) of DTG was determined using non-compartmental analysis based on intensive PK sampling at the following time points: pre-dose; 2, 3, 4, 8, and 24 hours post-dose at Week 2. Because PK was assessed for DTG, no participants in the EFV treatment group were analyzed.

The maximal concentration (Cmax), minimal concentration (Cmax), and concentration at the end of dosing interval (Ctau) of DTG were determined using non-compartmental analysis based on intensive PK sampling at the following time points: pre-dose; 2, 3, 4, 8, and 24 hours post-dose at Week 2. Because PK was assessed for DTG, no participants in the EFV treatment group were analyzed.

The plasma DTG pre-dose concentration (C0) of DTG was determined using limited/sparse PK sampling at Week 2, Week 12, and Week 24. C0 avg was calculated at Week 24 as the mean of the C0 of DTG at Week 2, Week 12, and Week 24. Because PK was assessed for DTG, no participants in the EFV treatment group were analyzed.

tmax of DTG was determined using non-compartmental analysis based on intensive PK sampling at the following time points: pre-dose; 2, 3, 4, 8, and 24 hours post-dose at Week 2. Because PK was assessed for DTG, no participants in the EFV treatment group were analyzed.

Relationship Between the Change From Baseline in Plasma HIV-1 RNA at Week 2 and the Indicated Plasma DTG PK Parameters [ Time Frame: Week 2 ] [ Designated as safety issue: No ]

Relationships between Week 2 plasma DTG PK parameters (AUC[0-tau] [area under the time concentration curve over the dosing interval], Cmax [maximal concentration], and Ctau [concentration at the end of the dosing interval]) and the change from Baseline in plasma HIV-1 RNA at Week 2 (calculated as the post-Baseline value minus the value at Baseline) was assessed using Pearson's correlation analyses. The Pearson's correlation coefficient is a measure of the correlation between plasma HIV-1 RNA and plasma DTG PK parameters and ranges from -1 to 1. A value of 0 indicates no statistical association; a value close to -1 or 1 indicates a higher association. Because PK was assessed for DTG, no participants in the EFV treatment group were analyzed.

Relationship Between the Change From Baseline in CD4+ Cell Counts at Week 96 and the Indicated Plasma DTG PK Parameters [ Time Frame: Week 96 ] [ Designated as safety issue: No ]

Relationships between plasma DTG PK parameters (AUC[0-tau] [area under the time concentration curve over the dosing interval], Cmax [maximal concentration], C0avg [average pre-dose concentration], and Ctau [concentration at the end of the dosing interval]) and the change from Baseline in CD4+ cell counts at Week 96 (calculated as the post-Baseline value minus the value at Baseline) was assessed using Pearson's correlation analyses. The Pearson's correlation coefficient is a measure of the correlation between CD4+ cell counts and plasma DTG PK parameters and ranges from -1 to 1. A value of 0 indicates no statistical association; a value close to -1 or 1 indicates a higher association.Because PK was assessed for DTG, no participants in the EFV treatment group were analyzed.

Relationships between log-transformed plasma DTG PK parameters (AUC[0-tau], Cmax, C0, C0avg, Ctau, and Cmin) and safety parameters (AE occurrence, maximum AE intensity, alanine aminotransferase [ALT], change from Baseline [CFB] in ALT, total bilirubin, CFB in total bilirubin, creatine kinase, CFB in creatine kinase, triglycerides, CFB in triglycerides, lipase, CFB in lipase, total cholesterol [TC], CFB in TC) was assessed using Pearson's correlation analyses. The Pearson's correlation coefficient is a measure of the correlation between safety parameters and plasma DTG PK parameters and ranges from -1 to 1. A value of 0 indicates no statistical association; a value close to -1 or 1 indicates a higher association. The presence of >=1 AE was used for AE occurrence. The most severe AE grade/intensity was used for maximum AE intensity. Maximum laboratory values per participant were used for safety parameters. CFB was calculated as the post-Baseline value minus the value at Baseline.

Relationship Between Gastrointestinal System Organ Class AEs of Special Interest at Week 96 and the Indicated Plasma DTG PK Parameters [ Time Frame: Week 96 ] [ Designated as safety issue: No ]

Logistic regressions were performed to examine the correlation between plasma DTG PK parameters (AUC[0-tau] [area under the time concentration curve over the dosing interval], Cmax [maximal concentration], Ctau [concentration at the end of the dosing interval], and C0avg [average pre-dose concentration]) on log scales and the presence of gastrointestinal system organ class AEs (abdominal pain, diarrhea, nausea, and vomiting) at Week 96. Data are presented as estimates from logistic regression, which is a measure of the association between AEs of special interest and plasma DTG PK parameters. A value of 0 indicates no statistical association; a large absolute value of the estimate indicates higher association. Because PK was assessed for DTG, no participants in the EFV treatment group were analyzed. Results are presented for participants in any DTG group (overall DTG).

approved therapy for HIV-1 infection, used as an internal study control

Detailed Description:

This Phase IIb study in HIV-infected antiretroviral naive adult subjects will include a dose-ranging evaluation of GSK1349572 10mg, 25mg and 50mg once daily blinded doses and a control arm of open label efavirenz 600mg once daily. Background ART for all study subjects will be chosen by the investigators and will be either Truvada or Epzicom/Kivexa. Data from the three doses of GSK1349572 will be compared on the basis of antiviral activity, safety/tolerability and pharmacokinetics over 16-24 weeks.

Several planned interim analyses will evaluate data in real time; any doses considered inferior will be dropped and subjects on those doses of GSK1349572 will have the option to switch to either the highest dose still under investigation or the selected dose. Subjects will be able to remain in the study, unless they reach a stopping criterion, for at least 96 weeks.

ViiV Healthcare is the new sponsor of this study, and GlaxoSmithKline is in the process of updating systems to reflect the change in sponsorship.

Eligibility

Ages Eligible for Study:

18 Years and older (Adult, Senior)

Genders Eligible for Study:

Both

Accepts Healthy Volunteers:

No

Criteria

Inclusion Criteria:

HIV-1 infected male or female adults at least 18 years of age. Women capable of becoming pregnant must use appropriate contraception during the study (as defined by the protocol);

HIV-1 infection with a screening plasma HIV-1 RNA greater than or equal to 1000copies/mL;

CD4+ cell count greater than or equal to 200cells/mm3 (or higher as local guidelines dictate);

ART-naive (less than or equal to 10 days of prior therapy with any antiretroviral agent). Any previous exposure to an HIV integrase inhibitor other than GSK1349572 will be exclusionary.

No evidence of viral resistance to any antiretroviral drug indicative of primary transmitted resistance at screening;

Able to understand and comply with protocol requirements;

Able to provide written informed consent prior to screening;

French subjects: In France, a subject will be eligible for inclusion in this study only if either affiliated to or a beneficiary of a social security category.

Note: Subjects starting abacavir as part of the NRTI backbone must have been screened and be negative for the HLA-B*5701 allele.

Exclusion Criteria:

Any pre-existing or serious mental or physical disorder which could compromise ability to comply with the protocol or compromise subject safety;

Women who are pregnant or breastfeeding;

An active AIDS-defining condition at the screening visit;

Previous participation in an experimental drug and/or vaccine trial(s) within 30 days or 5 half-lives;

History of clinically relevant pancreatitis or hepatitis within the previous 6 months, including HBsAg positive result. Asymptomatic HCV infection will not be exclusionary, however subject who will require HCV therapy during the trial should be excluded. Any subject with a history of liver cirrhosis with or without hepatitis viral co-infection will be excluded.

Any condition which could interfere with the absorption, distribution, metabolism or excretion of the drug;

Alanine aminotransferase (ALT) greater than or equal to 3xULN and bilirubin greater than or equal to 1.5xULN (with >35% direct bilirubin);

Lipase greater than or equal to 3xULN;

Hemoglobin < 100 g/L(10 g/dL);

History of allergy to the study drugs or their components or drugs of their class;

Treatment with radiation therapy, cytotoxic chemotherapeutic agents, any agents with activity against HIV-1 or immunomodulators within 28 days prior to screening;

Treatment with an HIV-1 immunotherapeutic vaccine within 90 days prior to screening;

History of protocol-defined cardiac diseases;

Personal or family history of prolonged QT syndrome;

Any clinically significant finding, as specified in the protocol, on electrocardiograph (ECG);

Significant blood loss in excess of 500 mL within a 56 day period prior to screening visit;

Immunization within 30 days prior to first dose of investigational product;

French subjects: The subject has participated in any study using an investigational drug during the previous 60 days or 5 half-lives, or twice the duration of the biological effect of the experimental drug or vaccine - whichever is longer, prior to screening for the study or the subject will participate simultaneously in another clinical study.

Contacts and Locations

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Please refer to this study by its ClinicalTrials.gov identifier: NCT00951015